Current wave repeater



Feb 24. m5; 1,5223%? J. JAMMER CURRENT WAVE REPEATER Filed Sept. 19. 1919 Z: $hm fia-$hwat 2 (5 \JUJL Jill w I E m m fivvnfor Jamh J". Jam/War 9 6'" 4 i NEWTZORK, N. SK. ASS IGNOR TO WESTERN ELECTRIC COMI'ANY,

lNUURPURATf-SD, NEW YORK, i l. 2., A CORPORATION Oil? NEW YORK.

CURRENTW&.VE REPEA'JEER.

A lication filled September 19, 1919. Serial No. 324,876.

- v and useful Improvements in Current 'ave Repeaters, of which the following is i full, clear, concise, and exact description. The present invention relates to current wave amplification and particularly to twobe lines for other uses.

t-ion 'wn r repeating means for current waves. A czuure of the invention is the use of a single amplifying element for simultaneously reeating waves in both directions.

It is customary in. two-way repeating of current waves to divide the transmission "tine into two sections and to provides SQpllrate amplifying path for transmission in each direction between said sections. In this way the energy received from a line section is amplified and passed on to a. dilferent section rather than being merely reapplied to the same line. In case the transmissions in onedirection all difier from those in the other direction in some characteristic such as the frequency, it is possible by the use of a single amplifier. according to the pre ent invention. to receh'e energy frompne line' section, amplify 1t. and to apply it practically exclusively to another line section.

In the drawing Figs. 1 and 3 are schematic disgrsms of circuits adapted for two-way repeating of separate single frequencies. for instance,"in a carrier wave telegraph system, and Figs. 2 indie show arrangements that may be used for repcatin separate frequency ranges such as are met with in telephony.

In Fig. 1 the line section s between which two-way repeating is to he accomplished are indicated as 1 andfi. These may be multiple carrier-telegraph-lines which carry a plurality of separate frequencies forming individual comu' iiication-clr-lnnels or they may I Transmissionto the right in the figure is effected by frequencies C. C G which maybe the usual carrier frequencies while frequencies G, aud t},

are used for transmission to the left. The frequencies used fortransmission in one dirertion are prcfcml'ily intermediate ,.tl10se used for transmission in the opposite direcin accordance with the well-known staggered frequency carrier wavesy'stcms al tlwugh such an arrangement of the-frequencies is not necessary, but the present invention requires simply that the frequencies used in one direction be different from those used for the opposite direction. Although only three frequencies are indicated for each directionthere could of course be any desired number. Nets 3 and 4 respectively, are provided for balancing the lines 1 and 2 for the transmitted frequencies and the usual conjugate coils 5, 6. 9 and 7, 8. 10 enable waves to be received from and applied to each of the respective lines without. mutual interferonce. A' single amplifier .11 of any suitable type serves to repeat all the transmitted waves simultaneously in both directions between the line sections 1 and 2. For this purpose its input path 12 is related to both line'sections in common and its output path while the filters 17, 18 and 19, pass only the frequencies C, C and C, that are repeated from line section 1 to line section 2. By this provision a. wave of frequency C, for instance, received from line section 1 istransmittcd through the couplings 9 and 12, is amplified by amplifier 11. is impressed through coupling 13 and the filter 17 to the line section 2, but is prevented from being 4 reapplied to the line section 1 by the filters 14;. 15 and 16 each of which highly attenuates and substantially extinguishes current of frequency C.

In'similar manner, waves (rf'frequoncies C and C are selectively impressed upon linc section 2 in amplified form through filters l8 and 19 respectively and Waves'of frequo'nciep C C and'C are amplified and selectively"impressed upon line section 1, through. filters 14:, 15, 16 respectively. :'I lie :unplilied waves delivered to line section 2, For instance. are prevented from passing again to the input side of the amplifier by virtue of the well-known balanced arrange; ment of the coils 7, 8 and 10. 1

It should be noted that this invention is particularly adaptcdlo systems in which the frequencies transmitted in one direction 1 the opposite direction in which case only 'an upper limiting and a lower limiting lter would be needed in the output circuit of the amplifier. These two filters would serve to separate all the frequencies transmitted in one direction from those transmitted in the opposite direction.

The band filters shown in Fig. 1 may be .used to pass more than the frequencies used direction comprise substantially single frequencies which are to be separately impressed on the respective line sections 1, 2, the band filters of Fig. 1 would be replaced by the simple tuned circuits such as. are shown in Fig. 3. Such circuits would be used in carrier telegraphy where the separate single frequencies used for transmitting in the two directions are staggered, for instance. In Fig. 3, only the line section 2 and the selective circuits for repeating into it are illustrated. The output multiplex wave from the amplifier through the couling 13 is impressed upon a' number of sep r direction, the filters 28 to 31 are provided to ectlve circuits such as32 and 33, there being one such circuit for each frequency transmitted. The tuned circuits 32 and 33 on the right of the connect-ions of transformer 13, are selective of those frequencies which are to be impressed on line section 2 and there would, of course, be other selective circuits on the left (but they are not shown), for selectin the frequencies to be transmitted to the line section 1. The res ective tuned circuits 32, 33, etc., are coup ed to correspondin tuned circuits 34, 35, etc., which are bri ged across the line section 2, for conveyingthe am lified currents to the line.

The circuit of ig. 2 is arranged for re' peating carrier waves that are modulated m accordance with a range of frequencies, for example by voice frequencies. In Patent No. 1,454,495, to H. J. Venues, May 8, 1923, a system is disclosed in which the same carrler frequency is used for transmission in both directions, but the signaling frequencies for the opposite directions are staggered. This effect is obtained by transmittmg in one direction a given side band,

the u per band, for example, obtained by modu ating the carrier b the voice, and transmitting the opposite band, in t is case the lower, 1n the other direction. he arrengement of Fig. 2 is adapted for such 9.

system. Transmission to the right may be affected by use of the upper bands C-i-S, for instance, where C denotes a carrier fre quency and S a range of signaling frequen-v cies, for example, voice frequencies. There are, of course, in practice, several carrier frequencies and it is convenient to have the corresponding side band of each modulated carrier wave, the upper bands, for instance, all transmitted in the same direction although this is not necessary.

Similarly, transmission to the left is effected by use of the lower bands designated in the drawings as C-S. The connections of Fig. 2 are substantially the same as those in Fig. 1, but a modification is made in the amplifier and the constants of the filters are of course, arranged to take care of the particular frequency bands transmitted. Amplifier 20 is preferably of the push-pull type consisting o the two thermionic amplifiers 21 and 22 connected oppositely as to their common output and input sides. Such an amplifier by virtue of its strai ht line characteristic is especiallyadapte to amplify over a large frequency range without distortionor inter-modulation of the various waves. Waves incoming from line 1 are amplified by amplifier 20 and impressed on the output circuit connected to both line sections.

Only the filters 2 1 to 27, however, are adapted to pass the upper-bands of the several carrier frequencies, and it is only on line section, 2, therefore, that these bands are imesse'd. For transmission in the opposite pass the lower bands of the several carrier frequencies.

. While the means for re ting telephonic messages has been descri ed in connection witha system in which the signalingfre- .quencies are staggered, it is equally adapted to a system in which the carrier frequencies are stag cred. For instance, the carrier waves in icated in Fig. 1 may each be modulated by voice frequency waves and an amlpllifier similar to 20 and the appropriate lters ma be inserted in place of those illustrated in ig. 1 to take care of the frequency ranges that are transmitted.

In either arrangement shown the path of the repeated waves could be made still more selective, of course, by placing other filters in the input of the repeater. An arrangement of this kind suitable for use with the system of Fig.2 is shown in Fig. where the 0+8 filters 32 to 35 are connected between the coil 9 associated with the line section 1 and the transformer 12 and where the OS filters 36 to 39 are connected between the coil 10 associated with line section 2 and the same transformer 12. A similar arrangement could be used with the system of Fig. 1, the only difference being in the constants of the filters which are necessarily I nets and conjugate coils.

The invention is not to be limited 'to'the particular filters illustrated nor to their exact mode of connection in the circuit. Also the invention is notto be limited to a single stage amplifier since a two or more stage amplifier could be used if desired and the term single amplifier as used in the claims is not to be understood as restricting the number of stages of amplification used. The amplifier likewise need not be the particular type shown nor is the invention to be otherwise limited by the specific embodiment which has been shown, but only by the scope of the appended claims.

What is claimed is:

A line for transmitting a plurality of current waves in each direction, each of substantially different frequency from all the others, a second similar line, a single amplifying circuit having its input side connected both of said lines and its output side connected to" both of said lines, and means for maintaining the output connection of the amplifier to each line substantially conjugate with respect to the input connection of the amplifier to the same line.

2. A line for transmitting a current wave in each direction, each wave modulated in accordance with signals, a second similar line, a single amplifying circuit having its input side connected to both of said lines and its output side connected to both of said lines, and balancing networks for maintaining the output connection of the amplifier to each line substantially conjugate with respect to the input connection of the amplifierto the same line. I

' Two lines, an amplifier for said lines,

a selective path from the first said line.

through said amplifier to the other line, and anther selective path from said other line through said amplifier to said first line.

4-. Two lines. and an amplifier having an input circuit coupled to both ofsaid lines, and an output circuit coupled to one of said lines through a selective path and to the other line through a selective path having different characteristics.

5. Two. lines, and means including selective paths and a single amplifier for simultaneously amplifying the energy on one line and iinpressmg it onthe other line and for amplifying the energy on said other has and impressing it on the first line without mutual interference.

6. A line for transmitting a plurality of frequencies in one direction and a plurality of different frequencies in the other direction, a second similar line, an amplifier for amplifying all of said frequencies simultaneously, and selective means for confining each said plurality of frequencies to the respective direction for transmission between said lin 7. Two lines for conveying a plurality of substantially difi'crentifrequencies in. each direction, and two-way repeating means-he-' tween said lines for all said fre uencies,said

means comprising a single amp ifier and se lective paths for, said frequencies.

8. Two lines for the transmission of cur-'- rent waves in both directions, the waves transmitted in one direction having a different characteristic from those transmitted in the other direction, a one-way selective path between said lines for the waves transmitted in one direction, another one-way selective path between said lines for the waves transmitted in the opposite'direction, and a single amplifier common to both said paths.

9. Two lines for theiransmission of current waves in each direction thereover, the waves transmitted in one direction having respectively different characteristics from those transmitted in the opposite direction, an amplifier for amplify'ing'all of said waves having its input and its output circuits each common to both of saidli'nes, and a'plurality of selective paths in said output ciruit be tween said amplifier and each of said lines for selectively'transmitting said waves.

10. Two lines for the transmission of current waves in each direction thereover, the waves transmitted in one direction having respectively different characteristics from those transmitted in the opposite direction, an amplifier for all of said waves having an input circuit common; to both lines, and an output circuit having two branches one for each line and filters having difierent characteristics in each of said branches.

11. A high frequency channel for two-way communication in which wave components of a given high frequency plus signal frequency are transmitted in one direction and wavecomponents of said high frequency minus signal frequency are transmitted in the opposite direction, said channel being divided into two sections, a repeater for repeatinggall said wave components'between said sections comprising a single amplifier having an input circuit common to said sections, an output circuit common to said sections, and filters for confining the sum frequencies to transmission in one direction between said sections and the difference frequencies to transmission in the opposite direction.

12. A line for transmitting a wave in one direction and a wave having a diii'erent characteristic in the opposite direction, said line being divided into two sections, an amplifier between said line sections for ampli tying both of said waves, and circuits associated with .said amplifier selective of the respec ive waves for causing the wave received over each line section to be transmitted only over the other line section.

13. A line for transmitting current waves of respectively difierent frequencies in-both directions, said line being divided into two sections, a balancing circuit for each section and a" conjugate connection for each section having input and output terminals which are mutually neutral with respect to each other, an amplifier having input and output circuits, the said output terminals of each line section being connected with the input circuit of said amplifier, and connections between the output circuit of said amplifier -and the input terminals of each line section, said connections including selective means for causing the waves in coming from each line section to be impressed only on the other line section.

14. Two lines for the transmission of current waves 1n each dlIBCtlOH thereover, the

waves transmitted in one' direction having each line, and filters in each of said branches. 0

15. A high frequency channel for two-way communication in which wave components of a given high frequency plus signal frequency are transmitted in one direction and wave components of said high frequency minus signal frequency are transmitted in the opposite direction, said channel being divided into two sections, a repeater for repeating all of said wave components between said sections comprising a single amplifier having an input circuit common to said sections and an output tions, and filters in both said input and output circuits for confining the sum frequencies to transmission in one direction between said sections and the difference frequencies to transmission in the opposite direction. p

In witness whereof, I hereunto subscribe my name this 15th day of September A. D.,

JACOB S. JAMMER.

circuit common to said sec- 

